The disclosures of Japanese Patent Applications Nos. 2001-104359 filed on Apr. 3, 2001, 2001-104366 filed on Apr. 3, 2001 and 2001-393452 filed on Dec. 26, 2001, each including the specification, drawings and abstract, are incorporated herein by reference in their entireties.
1. Field of Invention
The invention relates to a support mechanism of an automobile steering system.
2. Description of Related Art
Many automobile steering systems include an airbag in a steering wheel to absorb the impact force of a steering wheel against the driver upon a head-on collision of a vehicle. However, some automobile steering systems include an energy absorbing mechanism in a support mechanism of the steering system to absorb the impact force transmitted to the steering wheel. Other automobile steering systems include both an airbag and an energy absorbing mechanism.
The steering system disclosed in Japanese Patent Application No. 4-113954 not only absorbs the impact force of an airbag mounted in a steering wheel against the driver but also withdraws a steering column toward the front of the vehicle according to whether the driver fastens a seatbelt. This steering system thus maintains an appropriate distance between the steering wheel and the driver, thereby further reducing the impact force.
In order for the airbag to cooperate with a column moving mechanism, the above steering system includes various members for establishing a cooperative state between the airbag and the column moving mechanism, and a controller for controlling the cooperative relation therebetween. Therefore, in the above steering system, various constituent members are arranged around the steering column to allow the airbag and the column moving mechanism to cooperate with each other. This complicates the structure of the steering system and also significantly increases the costs. Moreover, for the above steering system, sufficient consideration have not been given regarding how the energy absorption amount of the support mechanism of the steering system is set according to whether the driver fastens a seatbelt and the seated position of the driver.
The invention thus provides a simplified support mechanism of a steering system that is capable of absorbing a different amount of impact energy according to whether the driver fastens the seatbelt and the seated position of the driver, and that does not cooperate with an airbag mounted in a steering wheel.
A first aspect of the invention relates to a support mechanism of a steering system, and more particularly, relates to a support mechanism of a steering system that is supports a steering column to a port of a vehicle body. The steering column that supports a steering shaft so that the steering shaft is rotatable in a circumferential direction. Basically, the support mechanism according to the first aspect of the invention includes an energy absorbing mechanism mounted in the support portion on a side of at least one of the steering column and the vehicle body, and capable of changing an energy absorption amount. The support mechanism reduces the energy absorption amount of the energy absorbing mechanism when a driver fastens a seatbelt and increases the energy absorption amount of the energy absorbing mechanism when the driver does not fasten the seatbelt.
In the support mechanism of the steering system according to the first aspect of the invention (first support mechanism), the energy absorbing mechanism may include a support member fixed to the steering column, a support pin extending through a longitudinal long hole in the support member, and attached to a part of the vehicle body to support the steering column to the vehicle body through the support member, an energy absorbing member mounted in the support member, and capable of being deformed by the support pin when the support pin moves relative to the long hole within the long hole, and an actuator that changes an amount of a deforming action on the energy absorbing member according to whether the driver fastens the seatbelt. The actuator reduces the amount of the deforming action on the energy absorbing member when the driver fastens the seatbelt, and increases the amount of the deforming action on the energy absorbing member when the driver does not fasten the seatbelt.
In the support mechanism according to the first aspect of the invention (second support mechanism), the energy absorbing mechanism may include an energy absorbing member mounted on a side of the vehicle body, and moving relative to the steering column in a longitudinal direction of the steering column, a deforming member mounted on a side of the steering column, that deforms the energy absorbing member while the deforming member is moving relative to the energy absorbing member, and an actuator that changes the amount of the deforming action of the deforming member on the energy absorbing member according to whether the driver fastens the seatbelt. The actuator reduces the amount of the deforming action on the energy absorbing member when the driver fastens the seatbelt, and increases the amount of the deforming action on the energy absorbing member when the driver does not fasten the seatbelt.
In the support member according to the first aspect of the invention (third support mechanism), the energy absorbing mechanism may include a support member fixed to the steering column, a support pin extending through a longitudinal long hole in the support member, and attached to a part of the vehicle body to support the steering column to the vehicle body through the support member, and first and second energy absorbing members mounted in the support member, and capable of being deformed by the support pin when the support pin moves relative to the long hole within the long hole. The support pin deforms the first energy absorbing member when the driver fastens the seatbelt, and deforms the first and second energy absorbing members simultaneously when the driver does not fasten the seatbelt.
A second aspect of the invention relates to a support mechanism of a steering system that supports to a steering column to a part of a part of a vehicle body. The steering column supports a steering shaft so that the steering shaft is rotatable in a circumferential direction. This support mechanism includes an energy absorbing mechanism mounted in the support portion on a side of at least one of the steering column and the vehicle body, and capable of changing an energy absorption amount. Provided that a driver does not fasten a seatbelt, the energy absorbing mechanism absorbs a larger amount of energy in the case where a seated position of the driver is ahead of a preset position as compared to the case where the seated position of the driver is in the preset position.
In the support mechanism according to the second aspect of the invention, the energy absorbing mechanism may include a support member fixed to the steering column, a support pin extending through a longitudinal long hole in the support member, and attached to a part of the vehicle body to support the steering column to the vehicle body through the support member, an energy absorbing member mounted in the support member, and capable of being deformed by the support pin when the support pin moves relative to the long hole within the long hole, and an actuator that changes an amount of a deforming action on the energy absorbing member. The actuator reduces the amount of the deforming action on the energy absorbing member when the seated position of the driver is in the preset position, and increases the amount of the deforming action on the energy absorbing member when the seated position of the driver is ahead of the preset position.
In the support mechanism according to the second aspect of the invention, the energy absorbing mechanism may include an energy absorbing member mounted on a side of the vehicle body, and moving relative to the steering column in a longitudinal direction of the steering column, a deforming member mounted on a side of the steering column, that deforms the energy absorbing member while the energy absorbing member is moving, and an actuator that changes an amount of a deforming action of the deforming member on the energy absorbing member according to the seated position of the driver. The actuator reduces the amount of the deforming action on the energy absorbing member when the seated position of the driver is in the preset position, and increases the amount of the deforming action on the energy absorbing member when the seated position of the driver is ahead of the preset position.
In the support mechanism according to the second aspect of the invention, the energy absorbing mechanism may include a support member fixed to the steering column, a support pin extending through a longitudinal long hole in the support member, and attached to a part of the vehicle body to support the steering column to the vehicle body through the support member, and first and second energy absorbing members mounted in the support member, and capable of being deformed by the support pin when the support pin moves relative to the long hole within the long hole. The support pin deforms the first energy absorbing member when the seated position of the driver is in the preset position, and deforms the first and second energy absorbing members simultaneously when the seated position of the driver is ahead of the preset position.
In the steering system supported by the first support mechanism of the first exemplary aspect of the invention, the driver may move forward and interfere with a steering wheel to move the steering column forward upon head-on collision of the vehicle. In this case, the support pin supporting the steering column moves backward within the long hole of the support member with a force corresponding to the impact force. While moving, the support pin deforms the energy absorbing member to absorb the impact energy in the energy absorbing member, thereby reducing the impact force of the steering wheel against the driver.
In this case, when the driver does not fasten the seatbelt, the actuator increases the amount of the deforming action on the energy absorbing member. The energy absorbing member thus absorbs a large amount of energy. On the other hand, when the driver fastens the seatbelt, the actuator reduces the amount of the deforming action on the energy absorbing member. The energy absorbing member thus absorbs a smaller amount of energy as compared to the case where the driver does not fasten the seatbelt.
In the steering system supported by the second support mechanism of the first exemplary aspect of the invention as well, the driver may move forward and interfere with a steering wheel to move the steering column forward upon head-on collision of the vehicle. In this case, the deforming member mounted on the side of the steering column moves relative to the energy absorbing member mounted on the side of the vehicle body. While moving, the deforming member pin deforms the energy absorbing member to absorb the impact energy in the energy absorbing member, thereby reducing the impact force of the steering wheel against the driver.
In this case, when the driver does not fasten the seatbelt, the actuator increases the amount of the deforming action on the energy absorbing member. The energy absorbing member thus absorbs a large amount of energy. On the other hand, when the driver fastens the seatbelt, the actuator reduces the amount of the deforming action on the energy absorbing member. The energy absorbing member thus absorbs a smaller amount of energy as compared to the case where the driver does not fasten the seatbelt.
In the steering system supported by the third support mechanism of the first exemplary aspect of the invention as well, the driver may move forward and interfere with a steering wheel to move the steering column forward upon head-on collision of the vehicle. In this case, the support pin supporting the steering column moves backward within the long hole of the support member with a force corresponding to the impact force. While moving, the support pin deforms the first energy absorbing member to absorb the impact energy in the first energy absorbing member, thereby reducing the impact force of the steering wheel against the driver.
In this case, when the driver does not fasten the seatbelt, one end of the second energy absorbing member is fixed to the support member. Therefore, the support pin deforms the second energy absorbing member simultaneously with the first energy absorbing member. As a result, a large amount of energy is absorbed. On the other hand, when the driver fastens the seatbelt, the second energy absorbing member is not fixed to the support member. Therefore, the support pin does not deform the second energy absorbing member. As a result, a smaller amount of energy is absorbed as compared to the case where the driver does not fasten the seatbelt.
The first, second and third support mechanisms of the first exemplary aspect of the invention are thus capable of changing the absorption amount of impact energy according to whether the driver fastens the seatbelt. The above support mechanisms make good use of the structure of a support mechanism that is essential for supporting the steering system to a part of the vehicle body. Accordingly, the above support mechanisms can be inexpensively manufactured with a relatively simple structure without complicating the structure of the steering system. As a result, significant increase in costs can be suppressed.
When the driver does not fasten the seatbelt and the seated position of the driver is the preset position, the support mechanism of the steering system of the second aspect of the invention provides the same effect as that provided by the above support mechanism of the first exemplary aspect when the driver fastens the seatbelt (i.e., the support mechanism absorbs a small amount of impact energy). When the driver does not fasten the seatbelt and the seated position of the driver is ahead of the preset position, the support mechanism of the steering system of the second exemplary aspect of the invention provides the same effect as that provided by the above support mechanism of the first exemplary aspect when the driver does not fasten the seatbelt (i.e., the support mechanism absorbs a large amount of impact energy).